FDC equivalent

FDC equivalent

BACKGROUND

BCTMP (mechanical pulping), is a new pulping process installed by PSPD, as it yields more than 90% pulp compared to less than 48% in chemical pulping. Higher pulp yield from the “Made in India BCTMP” unit is expected to provide a cost saving of ~3.7 Cr per annum of foreign exchange. This pulping unit requires sourcing of 150,000 tonnes (per annum) of locally produced wood. This massive raw material requirement has to be met through farm forestry plantation activities which can create significant livelihood opportunities for farmers.

Unlike chemical pulping, BCTMP requires raw material of certain wood features that give the required bulk and collapsibility for successful production of mechanical pulp. It is observed that 8-year-old plantation grown Eucalyptus (mature wood) has the acceptable traits for mechanical pulping. In addition to high pulp yield, mechanical pulp has higher bulk, stiffness, opacity, and softness but lower strength and brightness, due to the high lignin content in mature wood. Traditionally mechanical pulp was used for newspapers, books and magazines requiring low paper quality and longevity. The use of mechanical pulp is increasing worldwide due to the high yield from the process and increasing cost of fiber resources. BCTMP pulp can be used to pack the inner layers of paper board, along with chemical pulp in the outer layers, to give the same look and quality as boards made entirely of chemical pulp. Currently PSPD procures 8 year old Eucalyptus wood at a premium price, available only with the Forest Development Corporations (FDC) for mechanical pulping, which may not be available after a few years’ harvests. Wood from farmlands, especially in the core area is generally harvested at 4 years. Experiments with short rotation Euca wood indicated some parameters to be lower than that of FDC wood whereas other parameters like pulp brightness and strength are in the acceptable range. It is necessary to evaluate the pulp quality of 4 year old farm grown wood mixed in a certain proportion with FDC wood.

Other alternative species like Casuarina, Corymbia, Euca hybrids and Subabul have not been evaluated to determine the site effect. PSPD has a pilot facility where mechanical pulping experiments can be taken up to evaluate each parameter precisely. It is proposed to jointly evaluate alternative species such as Casuarina, Corymbia, Euca hybrids and Subabul of different ages to identify the key parameters of different species from multiple sites, in comparison to the FDC and 4 year Euca clones procured for chemical pulping. Evaluation of alternative species will help to focus on the key traits to be improved for use in BCTMP process. The current proposal aims to understand the parameters of each species for developing suitable planting material specifically for the BCTMP mill.

SUMMARY OF PROPOSAL:

Casuarina is known for its higher density and brightness than 4 year old Euca wood, while Corymbia hybrid has long fiber and low lignin, and Subabul has light coloured wood with long fibres. It is also established that the properties of wood currently obtained for mechanical pulping varies with age and location of harvest. We propose to evaluate the mechanical pulp traits in different species of different ages in PSPD’s pilot plant. A multi factorial study is proposed to understand the changes in wood properties across different ages and locations for identifying suitable wood for mechanical pulping. The study includes the following.

1. Assess the wood properties through mechanical pulping from Casuarina/Corymbia/Euca hybrids and Subabul, grown at 4, 5, 6, 7 and 8 years.
2. Assess the impact of site in alternative species grown at three locations of different agro-climatic zones.
3. Ascertain the impact of different variables (species; age; location; wood properties) for determining the parameters of an ideal wood for mechanical pulping using computational modelling.

PROPOSED BENEFIT AND OUTCOME

The proposed project is expected to identify the suitable wood for mechanical pulping, grown in farmers field, which would bring in alternate supply, improved requisite wood availability as well as huge cost saving.

TEAM AND TIMELINE

The experiments require 3 times testing of the samples, mentioned in the above table and require a time span of 3 years (Sep 2021 to Sep 2023) due to the staggered availability of materials. The following team is accountable for the project